A family sailing around the world and three others are feared to be lost at sea after their boat went missing three weeks ago after communicating with a meteorologist about an incoming storm. Search-and-rescue teams continue to look for signs of the historic schooner along the coast of New Zealand. NBC's Sara James reports.

By Henry Austin and Miriam Firestone

The "biggest ever" search of the seas surrounding New Zealand turned up no sign of an American schooner that has been missing for more than three weeks, officials said Friday.

Search and Rescue officer Neville Blakemore said the 70-foot vessel “probably had a catastrophic event” while traveling from New Zealand to Newcastle, Australia.

“The areas that have been searched have been absolutely massive and the area searched is the biggest area the Rescue Coordination Center of New Zealand has ever undertaken,” Blakemore said. “The comprehensive search by the Orion [aircraft] the last couple of days has indicated that if the yacht was still afloat they would have seen it in the search area. So we are assuming that it's not in the search area and thus probably had a catastrophic event.”

St. Andrews Historic Seaport and Commercial Marina / AP file

David Dyche, skipper of the 70-foot vessel Nina.

Blakemore added that he was refusing to give up hope of finding survivors but said the search was now focusing on debris from wreckage.

The New Zealand Herald identified four of the people on the vessel as David Dyche, 58; his wife, Rosemary, 60; their son David, 17; and Evi Nemreth, 73, of Boulder, Colo., a maritime technology expert and retired University of Colorado professor. A 35-year-old British man, a 28-year-old American man and an 18-year-old American woman were also on board.

A storm was reported near the vessel's last known location on June 4, the day the Nina vanished. It featured winds gusting up to 70 mph and 26-foot waves.

New Zealand-based meteorologist Bob McDavitt told the Associated Press that one of the crew was concerned about the conditions when she called on a satellite phone on June 4.

"The weather's turned nasty, how do we get away from it," McDavitt quoted Nemreth as asking him.

He added: "She was quite controlled in her voice, it sounded like everything was under control."

Stephen Western / AFP - Getty Images, file

The Nina is seen at sea in January 2012.

Friends in Panama City, Fla., where the Nina often moored, told NBC station WJHG that David Dyche was an “accomplished captain” and said they were refusing to give up hope.

Blakemore, the rescue official, refused to rule out the possibility of survivors. However, he said that the “logical conclusion” is that the boat sank rapidly, preventing the seven strong crew from sending out an SOS.

Unlike many locator beacons, he said that the one aboard Nina was not activated by water pressure and wouldn’t start automatically if the boat sank. However, he maintained that it would be unlikely that a craft the size of the Nina would sink.

“If the vessel got knocked over by a rogue wave it would have happened very, very quickly and they may not have had time to, to launch any life-saving equipment,” Blakemore added.

On her Facebook page, Rosemary Dyche said her family had planned a world tour.

“I am now on an adventure of a lifetime going around the world with my Wonderful husband who is my best friend and our youngest son," she wrote . "But I do Miss my 2 older sons Justin and Kevin and my grand kids Katelynn and Sean my mom. And all my friends. But we have to do it now while we can.”